Improvement in expanding mandrels



F. H. VANNAN. Expanding Mandrel.

No. 202,768. Patented April 23, 1878.

N. PEI'ER5. FNOTCLLITHOGRAP UNITED STATES PATENT OFFICE.

FORBES H. VANNAN, OF WILKESBARRE, PENNSYLVANIA.

IMPROVEMENT IN EXPANDING MANDRELS.

Specification forming part of Letters Patent No. 262,768, dated April23, 1878; application filed March 14, 1878.

To all whom it may concern:

Be it known that I, FORBES H. VANNAN, of Wilkesbarre, in the county ofLuzerne and State of Pennsylvania, have invented certain new and usefulImprovements in Expanding Mandrels and I do hereby declare that thefollowing is a full, clear, and exact description.

This invention relates to certain improvements in expanding mandrels formetal-working machines; and the invention consists in the specialconstruction and arrangement of pargls, which will be hereinafter morefully set fort In order to enable others skilled in the art to which myinvention appertains to make and use the same, I will now proceed todescribe its construction and operation, reference being had to theaccompanying drawings, which form a part of this specification, and inwhich- Figure 1 is a side elevation of my expanding mandrel, showing thewashers and nut in section. Fig. 2 is an end view of Fig. 1, with thenut and washer removed. Fig. 3 is a perspective view, showing a sectionof the bushing shown in Fig. 1. Fig. 4c is a View showing two of thewashers in perspective. Fig. 5 is a side elevation of the mandrel, andFig. 6 is an end and side view of the bushing shown in Fig. l inmodification.

The object of my invention is to dispense with the large number ofcumbersome heavy mandrels that are necessarily kept in allmachine-shops, and to save the time now lost in forcing articles uponthem; also, to save the expense of fitting mandrels to odd jobs whichthe standard mandrels will not fit, which is a continued expense in alljobbing and repair shops.

A represents the mandrel, having one end, B, provided with ascrew-thread. This mandrel is made tapering from the end B outward tothe end 0, as shown in figures of drawing.

forced upon the mandrel and turned down to the required diameter. Thisbush can be turned to a uniform diameter, as shown in Fig. 6 of drawingsor it can be turned with a series of faces, E, of increased diameters,as shown in Fig. 1 of drawings; or it can be turned to a taper when thenature of the work requires it. After the bush is turned as desired, thesize is stamped upon it, and the bush is cut into four or more equallongitudinal sections, F, as may be desired, each piece bearing thestamp indicating the size.

In the case of a series of faces of increased diameters the size isstamped upon each one of the series.

G G G are washers of varying sizes, of greater diameter than themandrel, so as to permit of their being forced after the bushing by thenut H.

The operation of this expanding mandrel is as follows: The article to beplaced upon the lathe is fitted upon the bushing as far up 011 themandrel as may be done easily and retain the sections of bushing inplace. Enough washers are then put on to reach the nut at a point nearthe front end of the screw-thread. The bushing carrying the work is thenforced up on the mandrel by the nut until a sufficiently snug fit ismade to hold the articles against the tool.

Having thus fully described my invention, what Iclaim as new, and desireto secure by Letters Patent, is

1. The combination of the mandrel A and bushing D, composed of two ormore separate sections adapted to slide on the mandrel A, with washers Gand nut H, as specified.

2. The improved bushing for expanding mandrels, consisting of separatesections, and adapted to slide lengthwise upon the surface of themandrel, as set forth.

In testimony that I claim the foregoing as my own I affix my signaturein presence of two witnesses.

F. H. VANN AN Witnesses H. K. MCLEAN, G. W. Moonns.

